This invention relates to the separation of selected components of a fluid, and more specifically, a polyphosphazene membrane for the separation of selective components from a fluid feedstream.
The separations of organic and inorganic components from fluid mixtures such as dispersions, emulsions, solutions and the like has been accomplished in the past by various means, for example, distillation, filtration, solvent extraction and a combination of these and other methods. One efficient means for separation of dissimilar phases or components of a solution involves the use of semipermeable membranes. In general, prior art membranes have been prepared from organic polymers which are usually stable up to approximately 90.degree. C. and are only effective in a limited range of media. As a result, the principle application of such prior art membranes has been in water desalination where the environment is relatively benign. Other potential uses such as petrochemical separations, in mineral processing, in catalytic reactions and in environmental clean-up, among a few, require use of a membrane in harsh environments, such as strongly caustic or acidic solutions or high temperature environments, and as such have yet to be considered as a significantly useful means for those chemical and physical separations involving such harsh environments.
Accordingly, an object of the subject invention is an improved inorganic membrane for the separation of various selected components from a feedstream fluid.
Another object of the subject invention is an improved inorganic membrane having superior flux and selective rejection characteristics over a broad range of temperature and environmental conditions.
Yet another object of the subject invention is a polyphosphazene membrane capable of being tailored for specific ion and/or solute rejection properties through the selective modification of side groups on the polymer chain.